Alex Newnham, a Ph.D. student of the RITM laboratory at Université Paris-Saclay, supervised by Professor Matthieu Crozet, will defend his Ph.D. thesis entitled “How the Costs of Mobility Define Adaptation to Labor Shocks,” on July 7, 2026. The PhD defense will be held in the Gaudemet Room (Building D of the Jean Monnet Faculty).
Composition of the jury:
- Benoît Schmutz-Bloch, Full Professor CREST / École Polytechnique – Reviewer
- Yanos Zylberberg, Full Professor, University of Bristol – Reviewer
- Camille Hémet, Full Professor, Université Paris 1-Panthéon-Sorbonne – Examiner
- Gregory Verdugo, Full Professor, CY Cergy Paris Université – Examiner
- Miren Lafourcade, Full Professor, Université Paris-Saclay – President
PhD Thesis Abstract: This thesis studies how workers spatially adjust to local labour demand shocks and what those adjustments cost, across three margins: long-distance migration, joint geographical and occupational reallocation, and daily commuting. Chapter 1 shows that preindustrial climate risk reduced inward migration in Europe and that this effect persists today through long-run prosperity differences. Chapter 2 estimates that geographical mobility costs for displaced French workers average 150,000 euros while occupational switching costs rang from 3,000 to 8,000 euros, explaining why 60% of displaced workers stay put despite large wage gains from moving. Chapter 3 finds that rising commuting distances for blue-collar and clerical workers reflect a spatial reorganisation of employment, not changing preferences. Together, the chapters provide micro-founded estimates of the frictions that govern worker spatial adjustment.